Bar soap manufacture



United States Patent 7 3,032,505 BAR SOAP MANUFACTURE Emmett P. Glynn, Chicago, and Carl 0. Hebenstreit, North Lake, Ill., assignors, by mesne assignments, to Armour & Company, Chicago, Ill., a corporation of Delaware No Drawing. Filed July 13, 1955, Ser. No. 521,891 4 Claims. (Cl. 252-122) This invention relates to improvements in the manufacture of toilet, bar soap compositions. In one of its aspects, this invention relates to a method for improving the milling and plodding properties of a solid soap composition containing inorganic salts causing shortness. In another of its aspects, this invention relates to a milled and plodded bar soap composition having improved lathering characteristics.

In the manufacture of toilet bar soap compositions several methods are employed in forming the bar. One method, for example, involves pouring molten soap into a plate frame or mold and allowing the soap to cool. In another method, one for producing a bar that floats, air is whipped into the slightly moist soap and it is continuously extruded in the form of a rectangularly cross-sectioned rod which is then cut into bars and stamped with the appropriate trade name. In the method which enjoys the most commercial popularity, neat soap as it comes from the production step is first mixed with acoloring agent and then dried to about a 10 to percent volatile (water) content. This dried soap leaves the dryer in the form of chips or flakes and is passed to a hasher where it is again broken up, mixed and extruded. Following this operation the soap, usually in the form of small pellets, is passed to another mixer or amalgamator where such ingredients as perfume and a germicide, as for example, hexachlorophene, are added. The resulting mixture is then passed to a mill where the soap is passed through several rolls, usually 3 to 5, for the purpose of converting the soap to what is known as the beta phase, which is a more water-soluble, higher lathering physical form. Following milling, the mixture is again plodded and extruded in the form of noodles and again plodded and finally extruded in a rectangularly cross-sectioned rod after which it is cut, stamped and wrapped.

Oftentimes in the production of the neat soap, due to improper settling, there is contained in the neat soap a quantity of inorganic salt, generally sodium chloride. The presence of inorganic salts in the soap is undesirable for the reason that it causes what is known as shortness in the physical processing steps. Shortness can be defined generally as the inability of the soap to be maintained in a continuous adhesive sheet, rod or mass, and one particularly undesirable manifestation of shortness is the refusal of the soap to pass from roll to roll in the milling operation. This problem is also present when it is desired to form milled and plodded toilet bars from a combination of soap and synthetic detergents since most synthetic detergents contain inorganic salts either as impurities or builders.

It is, therefore, an object of the present invention to provide an improvement in the manufacture of toilet bar soap compositions.

It is another object of this invention to provide a method for improving the milling and plodding properties of a solid soap composition containing inorganic salts causing shortness therein.

Still another object of this invention is to provide a milled and plodded toilet bar soap composition having improved lathering characteristics.

A further object of this invention is to provide a milled ICC 2 and plodded toilet bar soap composition having lathering characteristics equal to or greater than a bar containing the conventional amount of coconut oil soap, but containing less than half the conventional quantity of coconut oil soap.

Further and additional objects of this invention will become apparent as the specification proceeds.

In accordancewith the present invention, we have discovered that shortness due to inorganic salts experienced in the physical processing of solid soapcompositions into bars, especially in the milling and plodding operations,

can be substantially eliminated by the incorporation into the soap, preferably at the amalgamating stage, about A. to about 10 weight percent of a water-soluble alcohol ether represented by the general formula R(OR') OH wherein R is an alkyl group having from 1 to 4 carbon atoms, R- is an alkylene radical having from 2 to 3 carbon atoms and x is an integer of from 1 to 3.

Specific examples of water-soluble alcohol ethers which can be employed in accordance with our invention include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and dipropylene glycol monomethyl ether. These compounds are well-known chemicals and are available from several manufacturers, for example, from Carbide and Carbon Chemical Corporation under the trade names Cellosolve" and Carbitol, and from the Dow Chemical Company under the trade name Dowanol. The preferred group of compounds are the diethylene glycol mono ethers, that is, where x is 2 and R is ethylene.

As a practical matter, especially from the economic standpoint, not more than about 5 weight percent of al- 001101 ether need be employed to achieve the beneficial results of this invention, although a larger amount, up to about 10 weight percent, can be employed if a high percentage of inorganic'salt is encountered in the soap composition being processed.

In another aspect of our invention, we quite unexpectedly discovered that when incorporating the water-soluble alcohol ether into the solid soap composition, the resulting bar had improved lathering characteristics. This is a pleasant bonus when considered from the standpoint of improvement in processing. But apart from the improvement in processing, this discovery has important significance. Ordinarily, about 20% of coconut oil is added to tallow in order 'to form a toilet bar having the desired lathering characteristics in both warm and cold water. Historically, the cost of coconut oil has always been much greater than that of tallow because of the nature of its source and the limited supply. Therefore, the economic advantage to be gained in holding down the quantity of the higher priced coconut oil component in a milled toilet soap is obvious. Thus, we have found that by incorporating a small amount, not exceeding about 4 weight percent and preferably about 2 weight percent, of a watersoluble alcohol ether as hereinbefore defined, the amount of coconut oil soap ordinarily present in a conventional milled and plodded toilet bar can be diminished by more than 50% without impairing the lathering characteristics of the final product, and in fact improving the same. While a milled and plodded toilet bar can be produced which contains no coconut oil soap and still has good lathering characteristics, our experience has been that such a bar is subject to cracking in which the surface cracks in the bar present a bad appearance and the bar tends to break into smaller pieces. Cracking does not occur when a small percentage of coconut oil soap is maintained in the bar.

The following examples are set forth as illustrative of the present invention:

Example I The following ingredients in the amounts by weight designated were mixed, milled, plodded and formed into a bar using conventional equipment:

The mixture milled and plodded easily and the resulting bar had superior lathering characteristics.

A corresponding mixture omitting the three parts of diethylene glycol monobutyl ether milled with great difiiculty and was impossible to plod.

Example II The following ingredients in the amounts by weight designated were mixed, milled, plodded and formed into a bar using conventional equipment:

The mixture milled and plodded easily and the resulting bar had superior lathering characteristics.

Example 111 The following ingredients in the amounts by weight designated were mixed, milled, plodded and formed into a bar using conventional equipment:

Sodium tallow soap (anhydrous) 100 Sodium alkyl aryl sulfonate (anhydrous) (85% sulfonate, 15% Na SO 35 Water 15 Perfume 0.1 Color 0.02 TiO 0.1 Germicide 0.25

Dipropylene glycol monomethyl ether 2 The mixture milled and plodded easily even though a fairly large quantity of sodium sulfate was present.

Example IV The following ingredients in the amounts by weight designated were mixed, milled, plodded and formed into a bar using conventional equipment:

Sodium tallow tauride (2.1 parts of NaCl present therein) 35.4 Sodium tallow soap (anhydrous) 40.5 Sodium coconut oil soap (anhydrous) (0.25 parts of NaCl present in soap) 10.0 Water 11.1 Perfume 1.0

The mixture milled and plodded easily notwithstanding the presence of about 2.35 parts of sodium chloride.

While this invention has been described and exemplified in terms of its preferred embodiments, those skilled in the art will appreciate that modifications can be made without departing from the spirit and scope of the inven- Diethylene glycol monobutyl ether tion.

We claim:

1. A process for improving the milling and plodding properties of a sodium soap composition containing inorganic salts causing shortness which comprises incorporating in said soap composition about /2 to about 10 weight percent of a water-soluble alcohol ether represented by the formula R(OR') OH wherein R is an alkyl group containing from 1 to 4 carbon atoms, R is an alkylene radical having 2 to 3 carbon atoms and x is an integer of from 1 to 3.

2. A process according to claim 1 wherein about 2 weight percent of diethylene glycol monobutyl ether is employed.

3. A process according to claim 1 wherein about 2 weight percent of diethylene glycol monoethyl ether is employed.

4. A process according to claim 1 wherein about 2 weight percent of dipropylene glycol monomethyl ether is employed.

References Cited in the file of this patent UNITED STATES PATENTS 2,643,229 Walters June 23, 1953 FOREIGN PATENTS 327,393 Great Britain Apr. 1, 1930 411,295 Great Britain June 7, 19 34 

1. A PROCESS FOR IMPROVING THE MILLING AND PLODDING PROPERTIES OF A SODIUM SOAP COMPOSITION CONTAINING INORGANIC SALTS CAUSING SHORTNESS WHICH COMPRISES INCORPORATING IN SAID SOAP COMPOSITION ABOUT 1/2 TO ABOUT 10 WEIGHT PERCENT OF A WATER-SOLUBLE ALCOHOL ETHER REPRESENTED BY THE FORMUAL R(OR'')XOH WHEREIN R IS AN ALKYL GROUP CONTAINING FROM 1 TO 4 CARBON ATOMS AND X IS AN ALKYLENE RADICAL HAVING 2 TO 3 CARBON ATOMS AND X IS AN INTEGER OF FROM 1 TO
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